[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 54.001911][ T27] audit: type=1800 audit(1571791574.624:25): pid=8474 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 54.035609][ T27] audit: type=1800 audit(1571791574.634:26): pid=8474 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 54.072568][ T27] audit: type=1800 audit(1571791574.634:27): pid=8474 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.21' (ECDSA) to the list of known hosts. 2019/10/23 00:46:22 fuzzer started syzkaller login: [ 61.756181][ T1080] ------------[ cut here ]------------ [ 61.761672][ T1080] WARNING: CPU: 1 PID: 1080 at mm/khugepaged.c:1643 collapse_file+0x1f9d/0x4170 [ 61.770683][ T1080] Kernel panic - not syncing: panic_on_warn set ... [ 61.777277][ T1080] CPU: 1 PID: 1080 Comm: khugepaged Not tainted 5.4.0-rc4-next-20191022 #0 [ 61.785885][ T1080] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.795943][ T1080] Call Trace: [ 61.799243][ T1080] dump_stack+0x172/0x1f0 [ 61.803583][ T1080] ? collapse_file+0x1ef0/0x4170 [ 61.808523][ T1080] panic+0x2e3/0x75c [ 61.812449][ T1080] ? add_taint.cold+0x16/0x16 [ 61.817134][ T1080] ? printk+0xba/0xed [ 61.821139][ T1080] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 61.826610][ T1080] ? __warn.cold+0x14/0x35 [ 61.831131][ T1080] ? __warn+0xd9/0x1d0 [ 61.835209][ T1080] ? collapse_file+0x1f9d/0x4170 [ 61.840149][ T1080] __warn.cold+0x2f/0x35 [ 61.844394][ T1080] ? report_bug.cold+0x63/0xb2 [ 61.849159][ T1080] ? collapse_file+0x1f9d/0x4170 [ 61.854101][ T1080] report_bug+0x289/0x300 [ 61.858442][ T1080] do_error_trap+0x11b/0x200 [ 61.863041][ T1080] do_invalid_op+0x37/0x50 [ 61.867465][ T1080] ? collapse_file+0x1f9d/0x4170 [ 61.872394][ T1080] invalid_op+0x23/0x30 [ 61.876561][ T1080] RIP: 0010:collapse_file+0x1f9d/0x4170 [ 61.882105][ T1080] Code: a1 c0 ff 31 c9 ba 01 00 00 00 4c 89 fe 48 8b bd c0 fe ff ff e8 e4 e9 ec ff e9 b4 fd ff ff 4c 8b bd 88 fe ff ff e8 93 a1 c0 ff <0f> 0b 4c 8b a3 50 ff ff ff c7 85 80 fe ff ff 00 00 00 00 e9 05 f6 [ 61.901688][ T1080] RSP: 0018:ffff8880a7e87ad0 EFLAGS: 00010293 [ 61.907730][ T1080] RAX: ffff8880a7e38440 RBX: ffff8880a7e87c88 RCX: ffffffff81b2b688 [ 61.915679][ T1080] RDX: 0000000000000000 RSI: ffffffff81b2b9ad RDI: 0000000000000001 [ 61.923625][ T1080] RBP: ffff8880a7e87cb0 R08: ffff8880a7e38440 R09: fffff9400047e551 [ 61.931575][ T1080] R10: fffff9400047e550 R11: ffffea00023f2a87 R12: 0000000000000001 [ 61.939524][ T1080] R13: ffffea0002ff99c8 R14: 0000000000000000 R15: ffffea0002310000 [ 61.947486][ T1080] ? collapse_file+0x1c78/0x4170 [ 61.952401][ T1080] ? collapse_file+0x1f9d/0x4170 [ 61.957319][ T1080] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 61.963452][ T1080] ? khugepaged+0x21d0/0x4360 [ 61.968116][ T1080] ? trace_event_raw_event_mm_collapse_huge_page_isolate+0x370/0x370 [ 61.976599][ T1080] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 61.982382][ T1080] ? khugepaged_find_target_node+0x142/0x180 [ 61.988340][ T1080] khugepaged+0x2da9/0x4360 [ 61.992832][ T1080] ? __kasan_check_read+0x11/0x20 [ 61.997858][ T1080] ? __lock_acquire+0x16f2/0x4a00 [ 62.002876][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 62.008053][ T1080] ? finish_task_switch+0x147/0x750 [ 62.013236][ T1080] ? _raw_spin_unlock_irq+0x23/0x80 [ 62.018424][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 62.023694][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 62.029302][ T1080] ? lock_downgrade+0x920/0x920 [ 62.034128][ T1080] ? finish_wait+0x260/0x260 [ 62.038696][ T1080] ? lockdep_hardirqs_on+0x421/0x5e0 [ 62.043957][ T1080] ? trace_hardirqs_on+0x67/0x240 [ 62.048959][ T1080] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 62.055175][ T1080] ? __kthread_parkme+0x108/0x1c0 [ 62.060175][ T1080] ? __kasan_check_read+0x11/0x20 [ 62.065173][ T1080] kthread+0x361/0x430 [ 62.069220][ T1080] ? collapse_pte_mapped_thp+0xbe0/0xbe0 [ 62.074827][ T1080] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 62.080527][ T1080] ret_from_fork+0x24/0x30 [ 62.086440][ T1080] Kernel Offset: disabled [ 62.090823][ T1080] Rebooting in 86400 seconds..